Question

A mechanic pushes a 2.50��10 kg car from rest to a speed of v, doing 5000 J of work in the process. During this time, the car moves 25.0 m. Neglecting friction between the car and the road, find (a) v and (b) the horizontal force exerted on the car.

Answer 1

To find the speed of the car, use the work-energy theorem. The speed is 20 m/s. To find the horizontal force exerted on the car, use the equation Work = force * distance. The force is 200 N.

Step-by-step explanation:

To find the speed of the car, we can use the work-energy theorem. The work done on the car is equal to the change in its kinetic energy. In this case, the work done is 5000 J and the car moves 25.0 m. So, we can calculate the speed using the equation:

Work = (1/2) * mass * speed2

Substituting the given values, we have:

5000 J = (1/2) * (2.50 × 103 kg) * v2

Simplifying the equation, we find that the speed of the car is v = 20 m/s.

To calculate the horizontal force exerted on the car, we can use the equation:

Work = force * distance

Substituting the given values, we have:

5000 J = force * 25.0 m

Solving for the force, we find that the horizontal force exerted on the car is 200 N.